Jornal de Ciências da Terra e Mudanças Climáticas

Abstrato

Investigation of Climate Changes on Metabolic Response of Plants: Interactive Effects of Drought Stress and Excess UV-B

Hassan IA*, Basahi JM, Haiba NS and Kadi MW

Physiological and biochemical responses of bean (Vicia faba L.) plants to either supplementary ultraviolet (sUV-B) radiation, and/or water (WS) stress were investigated. Both stresses caused significant increases in H₂O₂ content and lipid peroxidation, indicating oxidative damage. Furthermore, increases in activities of stress markers indicated that sUV-B has a stronger stress effect than WS, and it caused greater membrane damage, as assessed by lipid peroxidation and osmolyte leakage.

The activities of ascorbate peroxidase (APX) and superoxide dismutase (SOD) were increased under both stresses when applied alone and in combination, while catalase (CAT) activity decreased under water stress as compared to the control. The combination of drought and UV-B, were more than additive, caused more severe damage than stress factors applied separately.

WS induced accumulation of UV-B absorbing secondary pigments (anthocyanin and flavonoids) which is likely to offer some protection from UV-B irradiation.